1. Field of the Invention
This invention relates to a surgical instrument, in general, and to a disposable surgical device for applying surgical clips to blood vessels or other body tissue, in particular.
2. Description of the Prior Art
In recent years, there have been proposed a number of surgical clip applicators for applying a clip to a blood vessel or the like. These instruments include an auxiliary cartridge or magazine capable of holding a sufficient number of surgical clips to accommodate the vessel-restricting requirements of most surgical procedures and of releasing clips, one at a time, successively as required. Specific examples of surgical instruments which utilize or include a cartridge or magazine are disclosed in U.S. Pat. Nos. 2,968,041; 3,232,089 and 3,777,538. The advantages of applicators of this type are enumerated at length in the specifications of the three patents just mentioned.
Until recently, the prior art did not suggest a system for applying surgical clips which incorporates a disposable cartridge detachably mounted on a permanent instrument. In this regard, two particularly advantageous surgical applicators of the magazine or cartidge type are disclosed in U.S. Pat. No. 4,152,920 issued May 8, 1979, and copending U.S. patent application Ser. No. 905,030, filed May 11, 1978.
Basically, all of the instruments mentioned above include a pair of movable jaws between which a clip is held preparatory to clinching. The jaws are drawn toward each other in response to a manual force applied by a surgeon to a handle arrangement operatively associated with the jaws by way of an actuator. In all of the known instruments, the parts which work in concert to accomplish application of a surgical clip are made entirely of metal, typically stainless steel. This is because a substantial force and mechanical advantage must be developed, through manual manipulation of the movable parts of the handle arrangement, in order to close the jaws to perform a clinching of the clip. As such, the structural designs of the prior art instruments do not readily lend themselves to the production of a fully disposable clip applier with an integral cartridge or magazine.
There is thus a need for a fully disposable clip applier which may be economically manufactured and which is capable of developing the substantial force and mechanical advantage necessary to perform a proper clip application in response to a manually applied force no greater than that force applied to actuate any of the prior art instruments. The present invention is directed toward filling that need.